\begin{tikzpicture}
    \tkzDefPoints{0/0/B, 4/0/C, 1.5/2/A, 3.5/2/D}
    \tkzDefMidPoint(A,B)  \tkzGetPoint{E}
    \tkzDefLine[parallel=through E](B,C)  \tkzGetPoint{f}
    \tkzInterLL(E,f)(C,D)  \tkzGetPoint{F}
    \tkzDrawPolygon(A,B,C,D)
    \tkzDrawSegments(E,F)
    \tkzLabelPoints[left](A,B,E)
    \tkzLabelPoints[right](C,D,F)
\end{tikzpicture}

